Applied Sciences

22 pages, 5035 KiB

Open AccessArticle

Reliability-Based Design Optimization of Structures Using the Second-Order Reliability Method and Complex-Step Derivative Approximation

by Junho Chun

Appl. Sci. 2021, 11(11), 5312; https://doi.org/10.3390/app11115312 - 7 Jun 2021

Cited by 10 | Viewed by 3416

Abstract

This paper proposes a reliability-based design optimization (RBDO) approach that adopts the second-order reliability method (SORM) and complex-step (CS) derivative approximation. The failure probabilities are estimated using the SORM, with Breitung’s formula and the technique established by Hohenbichler and Rackwitz, and their sensitivities [...] Read more.

This paper proposes a reliability-based design optimization (RBDO) approach that adopts the second-order reliability method (SORM) and complex-step (CS) derivative approximation. The failure probabilities are estimated using the SORM, with Breitung’s formula and the technique established by Hohenbichler and Rackwitz, and their sensitivities are analytically derived. The CS derivative approximation is used to perform the sensitivity analysis based on derivations. Given that an imaginary number is used as a step size to compute the first derivative in the CS derivative method, the calculation stability and accuracy are enhanced with elimination of the subtractive cancellation error, which is commonly encountered when using the traditional finite difference method. The proposed approach unifies the CS approximation and SORM to enhance the estimation of the probability and its sensitivity. The sensitivity analysis facilitates the use of gradient-based optimization algorithms in the RBDO framework. The proposed RBDO/CS–SORM method is tested on structural optimization problems with a range of statistical variations. The results demonstrate that the performance can be enhanced while satisfying precisely probabilistic constraints, thereby increasing the efficiency and efficacy of the optimal design identification. The numerical optimization results obtained using different optimization approaches are compared to validate this enhancement. Full article

(This article belongs to the Section Civil Engineering)

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22 pages, 542 KiB

Open AccessArticle

Variable Neighborhood Strategy Adaptive Search to Solve Parallel-Machine Scheduling to Minimize Energy Consumption While Considering Job Priority and Control Makespan

by Rujapa Nanthapodej, Cheng-Hsiang Liu, Krisanarach Nitisiri and Sirorat Pattanapairoj

Appl. Sci. 2021, 11(11), 5311; https://doi.org/10.3390/app11115311 - 7 Jun 2021

Cited by 7 | Viewed by 2878

Abstract

Environmental concerns and rising energy prices put great pressure on the manufacturing industry to reduce pollution and save energy. Electricity is one of the main machinery energy sources in a plant; thus, reducing energy consumption both saves energy costs and protects our planet. [...] Read more.

Environmental concerns and rising energy prices put great pressure on the manufacturing industry to reduce pollution and save energy. Electricity is one of the main machinery energy sources in a plant; thus, reducing energy consumption both saves energy costs and protects our planet. This paper proposes the novel method called variable neighborhood strategy adaptive search (VaNSAS) in order to minimize energy consumption while also considering job priority and makespan control for parallel-machine scheduling problems. The newly presented neighborhood strategies of (1) solution destroy and repair (SDR), (2) track-transition method (TTM), and (3) multiplier factor (MF) were proposed and tested against the original differential evaluation (DE), current practice procedure (CU), SDR, TTM, and MF for three groups of test instances, namely small, medium, and large. Experimental results revealed that VaNSAS outperformed DE, CU, SDR, TTM, and MF, as it could find the optimal solution and the mathematical model in the small test instance, while the DE could only find 25%, and the others could not. In the remaining test instances, VaNSAS performed 16.35–19.55% better than the best solution obtained from Lingo, followed by DE, CU, SDR, TTM, and MF, which performed 7.89–14.59% better. Unfortunately, the CU failed to improve the solution and had worse performance than that of Lingo, including all proposed methods. Full article

(This article belongs to the Section Applied Industrial Technologies)

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11 pages, 1420 KiB

Open AccessArticle

Analyzing Precision and Efficiency of Global Navigation Satellite System-Derived Height Determination for Coastal and Island Areas

by Jisun Lee, Jay Hyoun Kwon and Yong Lee

Appl. Sci. 2021, 11(11), 5310; https://doi.org/10.3390/app11115310 - 7 Jun 2021

Cited by 2 | Viewed by 2734

Abstract

The global navigation satellite system (GNSS)-derived height determination technique is applied in the field of surveying owing to the broad use of GNSS and the development of precise local geoid models. In Korea, this technique was officially adopted in 2020 for public surveying, [...] Read more.

The global navigation satellite system (GNSS)-derived height determination technique is applied in the field of surveying owing to the broad use of GNSS and the development of precise local geoid models. In Korea, this technique was officially adopted in 2020 for public surveying, such as urban facility mapping; it is also treated as an efficient way to unify the vertical datum of the inland and island areas of Korea. Here, GNSS surveying was conducted on 19 stations located in Korea’s coastal regions and islands, and GNSS-derived elevations were determined. When each GNSS-derived elevation was compared with elevations from spirit leveling, all stations showed differences of less than 3 cm when GNSS surveying was conducted for 4 h/day over two days; they were smaller than 5 cm with 2 h of surveying. These differences meet the standards of GNSS-derived elevations in Korea. In addition, GNSS-derived elevations were compared with those obtained via sea-crossing leveling in two regions, showing differences smaller than 1 cm. Sea-crossing leveling takes longer than GNSS-derived height determination, and its accuracy can be significantly affected by various environments, such as sea fog. Thus, GNSS-derived height determination represents a practical and useful technique. Full article

(This article belongs to the Special Issue GNSS Techniques for Land and Structure Monitoring)

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21 pages, 1110 KiB

Open AccessArticle

Carbon Availability and Nitrogen Mineralization Control Denitrification Rates and Product Stoichiometry during Initial Maize Litter Decomposition

by Pauline Sophie Rummel, Reinhard Well, Johanna Pausch, Birgit Pfeiffer and Klaus Dittert

Appl. Sci. 2021, 11(11), 5309; https://doi.org/10.3390/app11115309 - 7 Jun 2021

Cited by 10 | Viewed by 3408

Abstract

Returning crop residues to agricultural fields can accelerate nutrient turnover and increase N₂O and NO emissions. Increased microbial respiration may lead to formation of local hotspots with anoxic or microoxic conditions promoting denitrification. To investigate the effect of litter quality on [...] Read more.

Returning crop residues to agricultural fields can accelerate nutrient turnover and increase N₂O and NO emissions. Increased microbial respiration may lead to formation of local hotspots with anoxic or microoxic conditions promoting denitrification. To investigate the effect of litter quality on CO₂, NO, N₂O, and N₂ emissions, we conducted a laboratory incubation study in a controlled atmosphere (He/O₂, or pure He) with different maize litter types (Zea mays L., young leaves and roots, straw). We applied the N₂O isotopocule mapping approach to distinguish between N₂O emitting processes and partitioned the CO₂ efflux into litter- and soil organic matter (SOM)-derived CO₂ based on the natural ¹³C isotope abundances. Maize litter increased total and SOM derived CO₂ emissions leading to a positive priming effect. Although C turnover was high, NO and N₂O fluxes were low under oxic conditions as high O₂ diffusivity limited denitrification. In the first week, nitrification contributed to NO emissions, which increased with increasing net N mineralization. Isotopocule mapping indicated that bacterial processes dominated N₂O formation in litter-amended soil in the beginning of the incubation experiment with a subsequent shift towards fungal denitrification. With onset of anoxic incubation conditions after 47 days, N fluxes strongly increased, and heterotrophic bacterial denitrification became the main source of N₂O. The N₂O/(N₂O+N₂) ratio decreased with increasing litter C:N ratio and C_org:NO₃⁻ ratio in soil, confirming that the ratio of available C:N is a major control of denitrification product stoichiometry. Full article

(This article belongs to the Special Issue Denitrification in Agricultural Soils II)

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15 pages, 2845 KiB

Open AccessConcept Paper

A Pandemic Early Warning System Decision Analysis Concept Utilizing a Distributed Network of Air Samplers via Electrostatic Air Precipitation

by Joseph J. Bango, Sophia A. Agostinelli, Makayla Maroney, Michael Dziekan, Ruba Deeb and Gazi Duman

Appl. Sci. 2021, 11(11), 5308; https://doi.org/10.3390/app11115308 - 7 Jun 2021

Cited by 5 | Viewed by 2897

Abstract

The COVID-19 pandemic has highlighted the need for improved airborne infectious disease monitoring capability. A key challenge is to develop a technology that captures pathogens for identification from ambient air. While pathogenic species vary significantly in size and shape, for effective airborne pathogen [...] Read more.

The COVID-19 pandemic has highlighted the need for improved airborne infectious disease monitoring capability. A key challenge is to develop a technology that captures pathogens for identification from ambient air. While pathogenic species vary significantly in size and shape, for effective airborne pathogen detection the target species must be selectively captured from aerosolized droplets. Captured pathogens must then be separated from the remaining aerosolized droplet content and characterized in real-time. While improvements have been made with clinical laboratory automated sorting in culture media based on morphological characteristics of cells, this application has not extended to aerosol samples containing bacteria, viruses, spores, or prions. This manuscript presents a strategy and a model for the development of an airborne pandemic early warning system using aerosol sampling. Full article

(This article belongs to the Special Issue Advances in Analytical Methods and Applications)

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41 pages, 2333 KiB

Open AccessReview

Can Sustainable Packaging Help to Reduce Food Waste? A Status Quo Focusing Plant-Derived Polymers and Additives

by Imke Korte, Judith Kreyenschmidt, Joana Wensing, Stefanie Bröring, Jan Niklas Frase, Ralf Pude, Christopher Konow, Thomas Havelt, Jessica Rumpf, Michaela Schmitz and Margit Schulze

Appl. Sci. 2021, 11(11), 5307; https://doi.org/10.3390/app11115307 - 7 Jun 2021

Cited by 9 | Viewed by 6381

Abstract

The promotion of sustainable packaging is part of the European Green Deal and plays a key role in the EU’s social and political strategy. One option is the use of renewable resources and biomass waste as raw materials for polymer production. Lignocellulose biomass [...] Read more.

The promotion of sustainable packaging is part of the European Green Deal and plays a key role in the EU’s social and political strategy. One option is the use of renewable resources and biomass waste as raw materials for polymer production. Lignocellulose biomass from annual and perennial industrial crops and agricultural residues are a major source of polysaccharides, proteins, and lignin and can also be used to obtain plant-based extracts and essential oils. Therefore, these biomasses are considered as potential substitute for fossil-based resources. Here, the status quo of bio-based polymers is discussed and evaluated in terms of properties related to packaging applications such as gas and water vapor permeability as well as mechanical properties. So far, their practical use is still restricted due to lower performance in fundamental packaging functions that directly influence food quality and safety, the length of shelf life, and thus the amount of food waste. Besides bio-based polymers, this review focuses on plant extracts as active packaging agents. Incorporating extracts of herbs, flowers, trees, and their fruits is inevitable to achieve desired material properties that are capable to prolong the food shelf life. Finally, the adoption potential of packaging based on polymers from renewable resources is discussed from a bioeconomy perspective. Full article

(This article belongs to the Special Issue 10th Anniversary of Applied Sciences: Invited Papers in Materials)

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25 pages, 2527 KiB

Open AccessArticle

Statistical Approach to Potentially Enhance the Postbiotication of Gluten-Free Sourdough

by Bogdan Păcularu-Burada, Mihaela Turturică, João Miguel Rocha and Gabriela-Elena Bahrim

Appl. Sci. 2021, 11(11), 5306; https://doi.org/10.3390/app11115306 - 7 Jun 2021

Cited by 21 | Viewed by 3337

Abstract

Fermented products are permanently under the attention of scientists and consumers, both due to nutritional importance and health promoting effects. The fermented functional foods contribute to a more balanced diet and increase the immune responses (among many other health effects) with positive implications [...] Read more.

Fermented products are permanently under the attention of scientists and consumers, both due to nutritional importance and health promoting effects. The fermented functional foods contribute to a more balanced diet and increase the immune responses (among many other health effects) with positive implications for quality of life. In this sense, improving the sourdough’s fermentation to boost the biotic (postbiotic and paraprobiotic) properties of the sourdough-based products has positive impacts on the nutritional and functional properties of the final baked products. These enhanced sourdoughs can be obtained in controlled fermentation conditions and used as sourdough bread improvers or novel bioingredients. In this context, our work aimed to optimize, using statistical tools, a gluten-free sourdough based on chickpea, quinoa, and buckwheat fermentation with selected lactic acid bacteria (LAB) to enhance its postbiotic properties. The most important biotechnological parameters were selected by Plackett–Burman Design (PBD) and then Response Surface Methodology (RSM) was applied to evaluate the interactions between the selected factors to maximize the gluten-free sourdough’s properties. As a result, the optimized fermented sourdough had antimicrobial activity with inhibition ratios between 71 and 100% against the Aspergillus niger, Aspergillus flavus, Penicillium spp. molds and against the Bacillus spp endospore-forming Gram-positive rods. The optimized variant showed a total titratable acidity (TTA) of 40.2 mL NaOH 0.1N. Finally, the high-performance liquid chromatography (HPLC) analysis highlighted a heterofermentative profile for the organic acids from the optimized sourdough. Among flavonoids and polyphenols, the level of caffeic and vanillic acids increased after lactic acid fermentation. The comparison between the optimized sourdough and the control evidenced significant differences in the metabolite profiles, thus highlighting its potential postbiotication effect. Full article

(This article belongs to the Special Issue Advances of Lactic Fermentation for Functional Food Production)

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18 pages, 16049 KiB

Open AccessArticle

The Possibility to Recreate the Shapes of Objects on the Basis of Printer Vibration in the Additive Printing Process

by Andrzej Stańczak, Ireneusz Kubiak, Artur Przybysz and Anna Witenberg

Appl. Sci. 2021, 11(11), 5305; https://doi.org/10.3390/app11115305 - 7 Jun 2021

Cited by 2 | Viewed by 2888

Abstract

Information protection is an important safety issue in many human activity fields. Technological advances and related ubiquitous computerization bring new challenges in this area. In particular, the problem concerns the protection of devices against non-invasive acquisition processed information in ICT systems. It is [...] Read more.

Information protection is an important safety issue in many human activity fields. Technological advances and related ubiquitous computerization bring new challenges in this area. In particular, the problem concerns the protection of devices against non-invasive acquisition processed information in ICT systems. It is known that, e.g., VGA, DVI/HDMI interfaces or laser printer formatter systems that process visual signals are the effective sources of compromising electromagnetic emanations. The emission safety of the more and more commonly used 3D printers is less known. In many cases, the disclosure of information about printed objects might constitute an infringement of the state/industrial/commercial secret, copyright, patent protection, etc. In order to analyze the existing threat, a selected printer using FDM technology was tested. During the tests, simple objects were printed to identify the operation of the stepper motor and the movements of the printer head and the printer platform, which are sources of emissions in the secondary channels. The analyses performed focused on finding the correlation between the recorded vibration signals and the printer head movements when an object was printed. It was shown that the analysis of the registered sensitive signal runtimes and their spectrograms allowed to recreate the printed object shape. Three simple objects (a trihedron, a tube and a tetrahedron) were selected for testing because they include elements that allow the four major movements of the printer head to be easily recognized: along the X axis, along the Y axis, along an arc and diagonally (between the X and Y axes). The paper presents the test results and their analyses. Full article

(This article belongs to the Special Issue Celebrating Applied Sciences Reaches 20,000 Articles Milestone: Invited Papers in Acoustics and Vibrations Section)

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16 pages, 917 KiB

Open AccessArticle

The Effects of Plasma-Activated Water on Heavy Metals Accumulation in Water Spinach

by Chih-Yao Hou, Ting-Khai Kong, Chia-Min Lin and Hsiu-Ling Chen

Appl. Sci. 2021, 11(11), 5304; https://doi.org/10.3390/app11115304 - 7 Jun 2021

Cited by 20 | Viewed by 5054

Abstract

Toxic heavy metals accumulate in crops from the environment through different routes and may interfere with biochemical reactions in humans, causing serious health consequences. Plasma technology has been assessed for the promotion of seed germination and plant growth in several past studies. Therefore, [...] Read more.

Toxic heavy metals accumulate in crops from the environment through different routes and may interfere with biochemical reactions in humans, causing serious health consequences. Plasma technology has been assessed for the promotion of seed germination and plant growth in several past studies. Therefore, the aim of the present study was to evaluate whether the growth rate of plants can be increased with the application of non-thermal plasma, as well as to reduce the accumulation of heavy metals in leafy vegetables (water spinach). In this study, several kinds of plasma treatments were applied, such as treatment on the seeds (PTS + NTW), irrigation water (NTS + PAW) or both (PTS + PAW). The results of the study showed that the heavy metals accumulated in water spinach were affected by the heavy metals available in the soil. The bioconcentration factor (BCF) of Cd in water spinach decreased from 0.864 to 0.543 after plasma treatment in seed or irrigating water, while the BCF of Pb was low and did not show any significant changes. Therefore, the results suggest that plasma treatment may suppress Cd absorption, but not for Pb. In this study, plasma treatment did not help to improve the product yield of water spinach planted in Cd-added soil. In the future, fertilizers can be used to supply nutrients that are not provided by plasma-activated water to support the growth of water spinach. Full article

(This article belongs to the Special Issue Recent Advances in Applied Microbiology and Food Sciences)

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20 pages, 1227 KiB

Open AccessArticle

Brainware Computing: Concepts, Scopes and Challenges

by Eui-Nam Huh and Md Imtiaz Hossain

Appl. Sci. 2021, 11(11), 5303; https://doi.org/10.3390/app11115303 - 7 Jun 2021

Cited by 9 | Viewed by 3534

Abstract

Over the decades, robotics technology has acquired sufficient advancement through the progression of 5G Internet, Artificial Intelligence (AI), Internet of Things (IoT), Cloud, and Edge Computing. Though nowadays, Cobot and Service Oriented Architecture (SOA) supported robots with edge computing paradigms have achieved remarkable [...] Read more.

Over the decades, robotics technology has acquired sufficient advancement through the progression of 5G Internet, Artificial Intelligence (AI), Internet of Things (IoT), Cloud, and Edge Computing. Though nowadays, Cobot and Service Oriented Architecture (SOA) supported robots with edge computing paradigms have achieved remarkable performances in diverse applications, the existing SOA robotics technology fails to develop a multi-domain expert with high performing robots and demands improvement to Service-Oriented Brain, SOB (including AI model, driving service application and metadata) enabling robot for deploying brain and a new computing model with more scalability and flexibility. In this paper, instead of focusing on SOA and Robot as a Service (RaaS) model, we propose a novel computing architecture, addressed as Brainware Computing, for driving multiple domain-specific brains one-at-a-time in a single hardware robot according to the service, addressed as Brain as a Service (BaaS). In Brainware Computing, each robot can install and remove the virtual machine, which contains SOB and operating applications from the nearest edge cloud. Secondly, we provide an extensive explanation of the scope and possibilities of Brainware Computing. Finally, we demonstrate several challenges and opportunities and then concluded with future research directions in the field of Brainware Computing. Full article

(This article belongs to the Special Issue Cloud Computing Beyond)

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15 pages, 1583 KiB

Open AccessArticle

LTmatch: A Method to Abstract Pattern from Unstructured Log

by Xiaodong Wang, Yining Zhao, Haili Xiao, Xiaoning Wang and Xuebin Chi

Appl. Sci. 2021, 11(11), 5302; https://doi.org/10.3390/app11115302 - 7 Jun 2021

Cited by 7 | Viewed by 2999

Abstract

Logs record valuable data from different software and systems. Execution logs are widely available and are helpful in monitoring, examination, and system understanding of complex applications. However, log files usually contain too many lines of data for a human to deal with, therefore [...] Read more.

Logs record valuable data from different software and systems. Execution logs are widely available and are helpful in monitoring, examination, and system understanding of complex applications. However, log files usually contain too many lines of data for a human to deal with, therefore it is important to develop methods to process logs by computers. Logs are usually unstructured, which is not conducive to automatic analysis. How to categorize logs and turn into structured data automatically is of great practical significance. In this paper, LTmatch algorithm is proposed, which implements a log pattern extracting algorithm based on a weighted word matching rate. Compared with our preview work, this algorithm not only classifies the logs according to the longest common subsequence(LCS) but also gets and updates the log template in real-time. Besides, the pattern warehouse of the algorithm uses a fixed deep tree to store the log patterns, which optimizes the matching efficiency of log pattern extraction. To verify the advantages of the algorithm, we applied the proposed algorithm to the open-source data set with different kinds of labeled log data. A variety of state-of-the-art log pattern extraction algorithms are used for comparison. The result shows our method is improved by 2.67% in average accuracy when compared with the best result in all the other methods. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

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14 pages, 1848 KiB

Open AccessArticle

Performance Changes and Recovery Time in U20 and Older Handball Players after a High-Intensity Sprint Exercise

by Stefanie Klatt, Melanie Kossmann, Laura Hottenrott, Alexander Ferrauti and Frowin Fasold

Appl. Sci. 2021, 11(11), 5301; https://doi.org/10.3390/app11115301 - 7 Jun 2021

Cited by 1 | Viewed by 2855

Abstract

This study used a single bout of repeated high-intensity sprint exercise as a variable to compare the performance and recovery time of handball players within a typical age range for team sport athletes. Two test groups (U20 players, n = 12, mean age [...] Read more.

This study used a single bout of repeated high-intensity sprint exercise as a variable to compare the performance and recovery time of handball players within a typical age range for team sport athletes. Two test groups (U20 players, n = 12, mean age = 18 years; senior players, n = 17, mean age = 27 years) were observed during and after their performance of a high-intensity interval exercise consisting of four sets of 6 × 40 m all-out change-of-direction sprints. U20 players outperformed senior players in all sprint sets. The groups’ physiological responses and perceived exertion and stress levels were measured immediately before and after the exercise and also after 24, 48, and 72 h. Repeated measures ANOVAs revealed no interaction effects between age and measurement time points on jump height, muscle soreness, and perceived stress levels after the high-intensity interval exercise. However, the U20 athletes showed marginally, but not statistically significant lower creatine kinase (CK) values than the seniors 72 h after the exercise. The vagal heart rate variability (HRV) parameter rMSSD indicated a faster recovery for the U20 athletes compared to the senior players 24 h after the sprint intervals. Overall, the results demonstrate that repeated sprint intervals do not differently affect the physical performance ability (i.e., jump height) of U20 and senior players. Single parameters related to the players’ ability to recover, such as CK and HRV values, show some variations as a function of age. Based on this, coaches may want to consider a longer recovery period after a high-intensity exercise for senior players compared to younger ones. Full article

(This article belongs to the Special Issue Diagnostic and Interventions in Team Sports)

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11 pages, 1263 KiB

Open AccessArticle

In Vitro Cytotoxic Effects of Secondary Metabolites Present in Sarcopoterium Spinosum L.

by Jozef Hudec, Jan Mojzis, Marta Habanova, Jorge A. Saraiva, Pavel Hradil, Tibor Liptaj, Lubomir Kobida, Miroslav Haban, Maria Holovicova and Dominika Zvercova

Appl. Sci. 2021, 11(11), 5300; https://doi.org/10.3390/app11115300 - 7 Jun 2021

Cited by 4 | Viewed by 2813

Abstract

Sarcopoterium spinosum (L.) is a medicinal plant traditionally used for the treatment of various diseases including cancer in the Near- and Middle East. The fractions and constituents of the ethanol extract of S. spinosum were screened for in vitro cytotoxic activities on Jurkat [...] Read more.

Sarcopoterium spinosum (L.) is a medicinal plant traditionally used for the treatment of various diseases including cancer in the Near- and Middle East. The fractions and constituents of the ethanol extract of S. spinosum were screened for in vitro cytotoxic activities on Jurkat (acute T-lymphoblastic leukemia), HeLa (cervical adenocarcinoma), MCF-7 (mammary gland adenocarcinoma), Caco-2 (human colorectal adenocarcinoma), and MDA-MB-231 (mammary gland adenocarcinoma) cell lines using the MTT (3-(dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract was subsequently re-extracted with ethyl acetate and in its sub-fraction obtained by column chromatography three compounds (stachydrine, benzalkonium chloride and rutine) were the first time identified by nuclear magnetic resonance (NMR) analyses. The most active subfraction showed cytotoxic activity against HeLa, MCF-7, and Caco-2 cell lines. The three compounds mentioned, as standards of high-performance liquid chromatography (HPLC) quality, were studied individually and in combination. Cytotoxic activity observed might be due to the presence of benzalkonium chloride and rutin. Benzalkonium chloride showed the strongest growth suppression effect against HeLa cells (IC₅₀ 8.10⁻⁷ M) and MCF-7 cells (IC₅₀ 5.10⁻⁶ M). The mixture of stachydrine and benzalkonium chloride allowed a synergistic cytotoxic effect against all tested cancer and normal cells to be obtained. Anti-cancer activity of the plant extract of S. spinosum remains under-investigated, so this research describes how the three major compounds identified in the ethyl acetate extract can exert a significant dose dependent in vitro cytotoxicity. Full article

(This article belongs to the Special Issue Plant-Based Foods and Nutrition as Effective Components in Diet Sustainability)

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11 pages, 830 KiB

Open AccessArticle

Static Magnetic Fields Effects on Polysaccharides Production by Different Microalgae Strains

by Kricelle M. Deamici, Michele G. de Morais, Lucielen O. Santos, Koenraad Muylaert, Christine Gardarin, Jorge Alberto V. Costa and Céline Laroche

Appl. Sci. 2021, 11(11), 5299; https://doi.org/10.3390/app11115299 - 7 Jun 2021

Cited by 24 | Viewed by 3435

Abstract

Microalgae are able to produce many valuable biomolecules, such as polysaccharides, that presents a large diversity of biochemical structures and functions as antioxidant, antifungal, anticancer, among others. Static magnetic fields (SMF) influence the metabolism of microorganisms and has been shown as an alternative [...] Read more.

Microalgae are able to produce many valuable biomolecules, such as polysaccharides, that presents a large diversity of biochemical structures and functions as antioxidant, antifungal, anticancer, among others. Static magnetic fields (SMF) influence the metabolism of microorganisms and has been shown as an alternative to increase microalgae biomass, yield and compounds production. Especially, some studies have highlighted that SMF application could enhance carbohydrate content. This study aimed to evaluate different conditions of SMF on Spirulina and Chlorella in indoor and outdoor conditions, in order to confirm the influence of SMF on polysaccharides production, evaluating which polysaccharidic fraction could be enhanced by SMF and highlighting a possible modification in EPS composition. Starch from Chlorella and exopolysaccharides (EPS) from Spirulina were quantified and characterized. SMF increased the starch content in Chorella fusca biomass. EPS productions from A. platensis and Spirulina sp. were not significantly increased, and global composition appeared similar to the controls (constituted basically of 80–86% neutral sugars and 13–19% uronic acids). However, the monosaccharide composition analysis revealed a significant modification of composition, i.e., the amount of fucose, arabinose, rhamnose, galactose and glucuronic acid was increased, while the glucose content was decreased. SMF application led to significant modification of polysaccharides production and this study demonstrate that combining the outdoor conditions with SMF, the starch content and EPS composition was positively affected. Full article

(This article belongs to the Special Issue New Insight in Microalgae Cultivation and Downstream Processes: Route toward Sustainable and Cost-Effective Production)

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17 pages, 3303 KiB

Open AccessArticle

Increasing Resolution of Seismic Hazard Mapping on the Example of the North of Middle Russian Highland

by Igor B. Movchan, Zilya I. Shaygallyamova, Alexandra A. Yakovleva and Alexander B. Movchan

Appl. Sci. 2021, 11(11), 5298; https://doi.org/10.3390/app11115298 - 7 Jun 2021

Cited by 22 | Viewed by 3024

Abstract

The standard problem of engineering geophysics, solved for road and house building and other construction types, is in the localization of areas with increased mobility in the upper part of a geological cross-section and in the parameterization of this mobility in terms of [...] Read more.

The standard problem of engineering geophysics, solved for road and house building and other construction types, is in the localization of areas with increased mobility in the upper part of a geological cross-section and in the parameterization of this mobility in terms of seismic intensity. There is a standard approach, according to which researchers assess the elastic strength characteristics of the core to a depth of about 30 m, implement the accumulation of seismogram observations, simulate accelerograms for particular conditions and, taking into account the data of complex geophysical methods, calculate the increment of seismic intensity as one of the parameters of a seismic hazard. The final result of this approach has the form of a seismogenic hazard map and a set of recommendations including the consideration of identified areas with a significant increasing seismic intensity increment, due to the peculiarities of the geological structure of polygons. This result is reliable, but very expensive, and requires the development of primary estimations of the rock massif with reduced resistance to external loads, which would optimize the efforts in engineering drilling and in field geophysical measurements in order to densify their spatial grid in the vicinity of a priori known positions with an increased seismogenic hazard. In addition, relatively sparse grids of wells, as well as local geophysical profiles laid under conditions of a complicated landscape, do not accurately localize risky areas in order to focus the attention of builders on strengthening the specific part of raised constructions. Following the wishes of our customers and relying on long-term testing of our interpretational developments, we formed an approach to primary hazard forecasting based on remote sensing data and digital elevation models, which can be classified as data with relatively free access. This article presents the results of research which was based on these free-of-charge data and which was developed in the field of construction of ground engineering structures for agricultural purposes, where one of the factors of mobility in the upper part of a cross-section is intensive karstification. Basically, the construction area according to the general seismic zoning maps is seismologically passive, though the relatively fast dynamics of karst determines the relevance of the detailed seismic zoning. The results of our interpretations are verified by deep geological and structural reconstructions based on wave analogies. The representativeness of the final forecast was confirmed by subsequent seismic assessments, which is related to the scientific novelty of the presented article. The authors’ technology for the qualitative and quantitative interpretation of remote sensing data and digital elevation models with high resolution provides the opportunity to increase the spatial resolution of seismic microzonation forecasts, implemented by standard geophysical methods, and it determines the practical significance of completed research. Full article

(This article belongs to the Section Earth Sciences)

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12 pages, 1789 KiB

Open AccessFeature PaperArticle

Micro-Landscape Dependent Changes in Arbuscular Mycorrhizal Fungal Community Structure

by Stavros D Veresoglou, Leonie Grünfeld and Magkdi Mola

Appl. Sci. 2021, 11(11), 5297; https://doi.org/10.3390/app11115297 - 7 Jun 2021

Cited by 3 | Viewed by 3049

Abstract

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make [...] Read more.

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make them more or less predictable in time and space. Here we present results from three controlled experiments, where we manipulated two environmental parameters, habitat connectance and habitat quality, to address the degree to which plant roots in archipelagos of high connectance and invariable habitats are colonized with (i) less diverse and (ii) easier to predict AMF assemblages. We observed no differences in diversity across our manipulations. We show, however, that mixing habitats and varying connectance render AMF assemblages less predictable, which we could only detect within and not between our experimental units. We also demonstrate that none of our manipulations favoured any specific AMF taxa. We present here evidence that the community structure of AMF is less responsive to spatio-temporal manipulations than root colonization rates which is a facet of the symbiosis which we currently poorly understand. Full article

(This article belongs to the Special Issue Hide and Seek of Soil Microbes—Who Is Where with Whom and Why?)

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23 pages, 5739 KiB

Open AccessArticle

Optimal Fall Protection System Selection Using a Fuzzy Multi-Criteria Decision-Making Approach for Construction Sites

by Haifeng Jin and Paul M. Goodrum

Appl. Sci. 2021, 11(11), 5296; https://doi.org/10.3390/app11115296 - 7 Jun 2021

Cited by 7 | Viewed by 2571

Abstract

Construction falls are a leading cause of fatalities in almost every construction industry around the globe, and fall protection systems are the key measures to ensure the safety of labor crews. This study develops a fuzzy multi-criteria decision-making model integrating analytical hierarchy process, [...] Read more.

Construction falls are a leading cause of fatalities in almost every construction industry around the globe, and fall protection systems are the key measures to ensure the safety of labor crews. This study develops a fuzzy multi-criteria decision-making model integrating analytical hierarchy process, fuzzy set theory and Technique for Order Preference by Similarity to Ideal Solution approach to analyze the overall performance of various fall protection plans for construction projects, which focuses on evaluation and selection of the appropriate protection plan considering the most influential safety, productivity, and economy factors. Results show that the optimal plan can be effectively identified and determined among all potential alternatives. Besides, the model overcomes the shortcoming of weight value uncertainty and ambiguous decision information through membership function calculations. As a result, it provides guidance for the improvement of construction performance, intending to minimize fall risks, improve labor productivity, and save economical cost on the jobsites. Full article

(This article belongs to the Section Civil Engineering)

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15 pages, 1223 KiB

Open AccessFeature PaperArticle

Characterization and Biotechnological Potential of Two Native Marine Microalgae Isolated from the Tunisian Coast

by Jamila Ben Mohamed, Jihen Elleuch, Marwa Drira, Maria Ángeles Esteban, Philippe Michaud, Slim Abdelkafi and Imen Fendri

Appl. Sci. 2021, 11(11), 5295; https://doi.org/10.3390/app11115295 - 7 Jun 2021

Cited by 9 | Viewed by 3050

Abstract

Microalgae are attracting considerable interest worldwide. In the present study, two native microalgae strains isolated from Tunisian cost were identified as Chlamydomonas sp. and Navicula sp. We characterized their pigment and protein contents, as well as their carbohydrate and lipid productivity. The predominant [...] Read more.

Microalgae are attracting considerable interest worldwide. In the present study, two native microalgae strains isolated from Tunisian cost were identified as Chlamydomonas sp. and Navicula sp. We characterized their pigment and protein contents, as well as their carbohydrate and lipid productivity. The predominant fatty acids were found to be α-linolenic acid (C18:3n-3) and palmitoleic acid (C16:1n-7) for Chlamydomonas sp. and Navicula sp. strains respectively. Microalgae methanol extracts showed important in vitro antibacterial activity against all tested gram negative bacteria. Antioxidant activities of methanol extracts were investigated by determining radical scavenging activity according to DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay showed that the newly isolated microalgae were not toxic and have potential application in the fish feeds domain as a supplement in fish meal. Also, the biosorption of cadmium from aqueous solutions by microalgae living cells was evaluated. Large removal capacities were obtained with values ranging from 89.8% to 99.38%. These results are very promising as a starting point for a potential application of these new isolates for in situ bioremediation of heavy metals contaminating aqueous systems. Full article

(This article belongs to the Special Issue Underutilized Natural Sources in Food and Dietary Supplements)

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8 pages, 1982 KiB

Open AccessArticle

Comparison of Two Intergranular Corrosion Tests on EN AW-6016 Sheet Material

by Peer Decker, Ines Zerbin, Luisa Marzoli and Marcel Rosefort

Appl. Sci. 2021, 11(11), 5294; https://doi.org/10.3390/app11115294 - 7 Jun 2021

Cited by 2 | Viewed by 2985

Abstract

Two different intergranular corrosion tests were performed on EN AW-6016 sheet material, an ISO 11846:1995-based test with varying solution amounts and acid concentrations, and a standard test of an automotive company (PV1113, VW-Audi). The average intergranular corrosion depth was determined via optical microscopy. [...] Read more.

Two different intergranular corrosion tests were performed on EN AW-6016 sheet material, an ISO 11846:1995-based test with varying solution amounts and acid concentrations, and a standard test of an automotive company (PV1113, VW-Audi). The average intergranular corrosion depth was determined via optical microscopy. The differences in the intergranular corrosion depths were then discussed with regard to the applicability and quality of the two different test methods. The influence of varying test parameters for ISO 11846:1995 was discussed as well. The determined IGC depths were found to be strongly dependent on the testing parameters, which will therefore have a pronounced influence on the determined IGC susceptibility of a material. In general, ISO 11846:1995 tests resulted in a significantly lower corrosion speed, and the corrosive attack was found to be primarily along grain boundaries. Full article

(This article belongs to the Special Issue Factors That Affect the Corrosion of Aluminium Alloys)

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29 pages, 7950 KiB

Open AccessArticle

Adaptive Cruise Control for Cut-In Scenarios Based on Model Predictive Control Algorithm

by Chongpu Chen, Jianhua Guo, Chong Guo, Chaoyi Chen, Yao Zhang and Jiawei Wang

Appl. Sci. 2021, 11(11), 5293; https://doi.org/10.3390/app11115293 - 7 Jun 2021

Cited by 21 | Viewed by 4871

Abstract

In a cut-in scenario, traditional adaptive cruise control usually cannot effectively identify the cut-in vehicle and respond to it in advance. This paper proposes an adaptive cruise control (ACC) strategy based on the MPC algorithm for cut-in scenarios. A finite state machine (FSM) [...] Read more.

In a cut-in scenario, traditional adaptive cruise control usually cannot effectively identify the cut-in vehicle and respond to it in advance. This paper proposes an adaptive cruise control (ACC) strategy based on the MPC algorithm for cut-in scenarios. A finite state machine (FSM) is designed to manage vehicle control in different cut-in scenarios. For a cut-in scenario, a method to identify and quantify the possibility of cut-in of a vehicle is proposed. At the same time, a safety distance model of the cut-in vehicle is established as the basis for the state transition of the finite state machine. Taking the quantified cut-in possibility of a vehicle as a reference, the model predictive control (MPC) algorithm, which considers the constraints of driving safety and comfort, is used to realize coordinated control of the host vehicle and the cut-in vehicle. Simulink–Carsim simulation studies show that the ACC strategy for a cut-in scenario can effectively identify a cut-in vehicle and quantify the possibility of cut-in of the vehicle. Faced with a cut-in vehicle, the host vehicle using the ACC strategy can brake several seconds early and switch the following target to the cut-in vehicle. Meanwhile, the acceleration and jerk of the host vehicle changes within a reasonable range, which ensures driving safety and comfort. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

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12 pages, 26919 KiB

Open AccessArticle

Crawling Magnetic Robot to Perform a Biopsy in Tubular Environments by Controlling a Magnetic Field

by Eunsoo Jung, Jaekwang Nam, Wonseo Lee, Jongyul Kim and Gunhee Jang

Appl. Sci. 2021, 11(11), 5292; https://doi.org/10.3390/app11115292 - 7 Jun 2021

Cited by 2 | Viewed by 3237

Abstract

We developed a crawling magnetic robot (CMR), which can stably navigate and perform biopsies remotely in tubular environments by controlling a magnetic field. The CMR is composed of a crawling part and a biopsy part. The crawling part allows the CMR to crawl [...] Read more.

We developed a crawling magnetic robot (CMR), which can stably navigate and perform biopsies remotely in tubular environments by controlling a magnetic field. The CMR is composed of a crawling part and a biopsy part. The crawling part allows the CMR to crawl forward and backward via an asymmetric friction force generated by an external precessional magnetic field. The biopsy part closes or opens the cover of a needle to use the biopsy needle selectively with the control of the external precessional magnetic field. The cover of the biopsy part prevents damage to the tubular environments because the biopsy needle is inside the cover while the CMR is navigating. We developed the design of the proposed CMR using magnetic torque constraints and a magnetic force constraint, and then we fabricated the CMR with three-dimensional printing technology. Finally, we conducted an experiment to measure the CMR’s puncturing force with a load cell and conducted an experiment in a Y-shaped watery glass tube with pseudo-tissue to verify the crawling motion, the uncovering and covering motion of the biopsy needle, and the CMR’s ability to extract tissue with the biopsy needle. Full article

(This article belongs to the Special Issue Micro-Robotics)

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14 pages, 1291 KiB

Open AccessArticle

Indoor Positioning Systems Can Revolutionise Digital Lean

by Tuan-Anh Tran, Tamás Ruppert and János Abonyi

Appl. Sci. 2021, 11(11), 5291; https://doi.org/10.3390/app11115291 - 7 Jun 2021

Cited by 20 | Viewed by 4155

Abstract

The powerful combination of lean principles and digital technologies accelerates waste identification and mitigation faster than traditional lean methods. The new digital lean (also referred to as Lean 4.0) solutions incorporate sensors and digital equipment, yielding innovative solutions that extend the reach of [...] Read more.

The powerful combination of lean principles and digital technologies accelerates waste identification and mitigation faster than traditional lean methods. The new digital lean (also referred to as Lean 4.0) solutions incorporate sensors and digital equipment, yielding innovative solutions that extend the reach of traditional lean tools. The tracking of flexible and configurable production systems is not as straightforward as in a simple conveyor. This paper examines how the information provided by indoor positioning systems (IPS) can be utilised in the digital transformation of flexible manufacturing. The proposed IPS-based method enriches the information sources of value stream mapping and transforms positional data into key-performance indicators used in Lean Manufacturing. The challenges of flexible and reconfigurable manufacturing require a dynamic value stream mapping. To handle this problem, a process mining-based solution has been proposed. A case study is provided to show how the proposed method can be employed for monitoring and improving manufacturing efficiency. Full article

(This article belongs to the Special Issue Digital Transformation in Manufacturing Industry Ⅱ)

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18 pages, 2597 KiB

Open AccessArticle

Laser Therapy in the Treatment of Peri-Implantitis: State-of-the-Art, Literature Review and Meta-Analysis

by Massimo Pisano, Alessandra Amato, Pasquale Sammartino, Alfredo Iandolo, Stefano Martina and Mario Caggiano

Appl. Sci. 2021, 11(11), 5290; https://doi.org/10.3390/app11115290 - 7 Jun 2021

Cited by 17 | Viewed by 4514

Abstract

(1) Background: The treatment of the peri-implantitis is still challenging, and no consensus was found in the literature on which is the best treatment protocol. In recent years, numerous authors have proposed the use of the dental laser as an alternative and effective [...] Read more.

(1) Background: The treatment of the peri-implantitis is still challenging, and no consensus was found in the literature on which is the best treatment protocol. In recent years, numerous authors have proposed the use of the dental laser as an alternative and effective method for decontaminating the surface of infected implants. Therefore, the aim of this work was to examine the state-of-the-art on the use of lasers in the treatment of peri-implantitis through the literature. (2) Methods: An electronic search was conducted through the PubMed database; we selected and reviewed articles that evaluated the effects of laser irradiation in the treatment of peri-implantitis. (3) Results: The use of lasers seems to provide similar results if compared with conventional mechanical therapy. The included studies were divided into three groups based on the active medium of the laser used for the treatments being tested (Erbium: Yttrium Aluminum Garnet, CO₂ and diode laser). (4) Conclusions: The lasers showed positive results, on average, after 6 months of follow-up. Comparative clinical trials conducted with the aim to test the efficiency of laser irradiation, in addition to conventional therapy, indicate that this technique can induce similar results if compared to conventional therapy alone. Full article

(This article belongs to the Special Issue Innovative Techniques and Devices in Implant Surgical and Prosthetic Therapy)

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15 pages, 2892 KiB

Open AccessArticle

Evolution of Water-in-Oil Droplets in T-Junction Microchannel by Micro-PIV

by Hawa Ringkai, Khairul Fikri Tamrin, Nadeem Ahmed Sheikh and Shahrol Mohamaddan

Appl. Sci. 2021, 11(11), 5289; https://doi.org/10.3390/app11115289 - 7 Jun 2021

Cited by 7 | Viewed by 3506

Abstract

Water-in-oil droplets have huge importance in chemical and biotechnology applications, despite their difficulty being produced in microfluidics. Moreover, existing studies focus more on the different shape of microchannels instead of their size, which is one of the critical factors that can influence flow [...] Read more.

Water-in-oil droplets have huge importance in chemical and biotechnology applications, despite their difficulty being produced in microfluidics. Moreover, existing studies focus more on the different shape of microchannels instead of their size, which is one of the critical factors that can influence flow characteristics of the droplets. Therefore, the present work aims to study the behaviours of water-in-oil droplets at the interfacial surface in an offset T-junction microchannel, having different radiuses, using micro-PIV software. Food-grade palm olein and distilled water seeded with polystyrene microspheres particles were used as working fluids, and their captured images showing their generated droplets’ behaviours focused on the junction of the respective microfluidic channel, i.e., radiuses of 400 µm, 500 µm, 750 µm and 1000 µm, were analysed via PIVlab. The increasing in the radius of the offset T-junction microchannel leads to the increase in the cross-sectional area and the decrease in the distilled water phase’s velocity. The experimental velocity of the water droplet is in agreement with theoretical values, having a minimal difference as low as 0.004 mm/s for the case of the microchannel with a radius of 750 µm. In summary, a small increase in the channel’s size yields a significant increase in the overall flow of a liquid. Full article

(This article belongs to the Topic Medical Image Analysis)

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19 pages, 14820 KiB

Open AccessArticle

Fractional Order Processing of Satellite Images

by Manuel Henriques, Duarte Valério and Rui Melicio

Appl. Sci. 2021, 11(11), 5288; https://doi.org/10.3390/app11115288 - 7 Jun 2021

Viewed by 2039

Abstract

Nowadays, satellite images are used in many applications, and their automatic processing is vital. Conventional integer grey-scale edge detection algorithms are often used for this. This study shows that the use of color-based, fractional order edge detection may enhance the results obtained using [...] Read more.

Nowadays, satellite images are used in many applications, and their automatic processing is vital. Conventional integer grey-scale edge detection algorithms are often used for this. This study shows that the use of color-based, fractional order edge detection may enhance the results obtained using conventional techniques in satellite images. It also shows that it is possible to find a fixed set of parameters, allowing automatic detection while maintaining high performance. Full article

(This article belongs to the Special Issue Novel Advances of Image and Signal Processing)

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17 pages, 9731 KiB

Open AccessArticle

Experimental Validation of a Thermo-Electric Model of the Photovoltaic Module under Outdoor Conditions

by Klemen Sredenšek, Bojan Štumberger, Miralem Hadžiselimović, Sebastijan Seme and Klemen Deželak

Appl. Sci. 2021, 11(11), 5287; https://doi.org/10.3390/app11115287 - 7 Jun 2021

Cited by 5 | Viewed by 2481

Abstract

An operating temperature of the photovoltaic (PV) module greatly affects performance and its lifetime. Therefore, it is essential to evaluate operating temperature of the photovoltaic module in different weather conditions and how it affects its performance. The primary objective of this paper is [...] Read more.

An operating temperature of the photovoltaic (PV) module greatly affects performance and its lifetime. Therefore, it is essential to evaluate operating temperature of the photovoltaic module in different weather conditions and how it affects its performance. The primary objective of this paper is to present a dynamic thermo-electric model for determining the temperature and output power of the photovoltaic module. The presented model is validated with field measurement at the Institute of Energy Technology, Faculty of Energy Technology, University of Maribor, Slovenia. The presented model was compared with other models in different weather conditions, such as clear, cloudy and overcast. The evaluation was performed for the operating temperature and output power of the photovoltaic module using Root-Mean-Square-Error (RMSE) and Mean-Absolute-Error (MAE). The average RMSE and MAE values are 1.75 °C and 1.14 °C for the thermal part and 20.34 W and 10.97 W for the electrical part. Full article

(This article belongs to the Special Issue Solar Radiation: Measurements and Modelling, Effects and Applications—Volume II)

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17 pages, 9314 KiB

Open AccessArticle

Mean Dynamic Topography Modeling Based on Optimal Interpolation from Satellite Gravimetry and Altimetry Data

by Yihao Wu, Jia Huang, Hongkai Shi and Xiufeng He

Appl. Sci. 2021, 11(11), 5286; https://doi.org/10.3390/app11115286 - 7 Jun 2021

Cited by 4 | Viewed by 2435

Abstract

Mean dynamic topography (MDT) is crucial for research in oceanography and climatology. The optimal interpolation method (OIM) is applied to MDT modeling, where the error variance–covariance information of the observations is established. The global geopotential model (GGM) derived from GOCE (Gravity Field and [...] Read more.

Mean dynamic topography (MDT) is crucial for research in oceanography and climatology. The optimal interpolation method (OIM) is applied to MDT modeling, where the error variance–covariance information of the observations is established. The global geopotential model (GGM) derived from GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) gravity data and the mean sea surface model derived from satellite altimetry data are combined to construct MDT. Numerical experiments in the Kuroshio over Japan show that the use of recently released GOCE-derived GGM derives a better MDT compared to the previous models. The MDT solution computed based on the sixth-generation model illustrates a lower level of root mean square error (77.0 mm) compared with the ocean reanalysis data, which is 2.4 mm (5.4 mm) smaller than that derived from the fifth-generation (fourth-generation) model. This illustrates that the accumulation of GOCE data and updated data preprocessing methods can be beneficial for MDT recovery. Moreover, the results show that the OIM outperforms the Gaussian filtering approach, where the geostrophic velocity derived from the OIM method has a smaller misfit against the buoy data, by a magnitude of 10 mm/s (17 mm/s) when the zonal (meridional) component is validated. This is mainly due to the error information of input data being used in the optimal interpolation method, which may obtain more reasonable weights of observations than the Gaussian filtering method. Full article

(This article belongs to the Special Issue Advances in Applied Geophysics)

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15 pages, 13126 KiB

Open AccessArticle

Light-Induced Ring Pattern in a Dye-Doped Nematic Liquid Crystal

by Marcel G. Clerc, Gregorio González-Cortés, Paulina I. Hidalgo, Lucciano A. Letelier, Mauricio J. Morel and Jorge Vergara

Appl. Sci. 2021, 11(11), 5285; https://doi.org/10.3390/app11115285 - 7 Jun 2021

Cited by 2 | Viewed by 3217

Abstract

The use of dye-doped liquid crystals allows the amplification of the coupling of light and liquid crystals. Light can induce the self-organization of the molecular order. The appearance of ring patterns has been observed, which has been associated with phase modulation. However, the [...] Read more.

The use of dye-doped liquid crystals allows the amplification of the coupling of light and liquid crystals. Light can induce the self-organization of the molecular order. The appearance of ring patterns has been observed, which has been associated with phase modulation. However, the morphology and dynamics of the ring patterns are not consistent with self-modulation. Based on an experimental setup with two parallel coherence beams orthogonal to a liquid crystal cell, one of which induces photo-isomerization and the other causes illumination, the formation of ring patterns is studied. To use these two coherent beams, we synthesize methylred methyl ester as a dye-dopant, which is photosensitive only to one of the light beams, and a commercial E7 liquid crystal as a matrix. Based on a mathematical model that accounts for the coupling between the concentration of the cis-state and the order parameter, we elucidate the emergence of the rings as forming patterns in an inhomogeneous medium. The bifurcation diagram is analytically characterized. The emergence, propagation of the rings, and the establishment of the ring patterns are in fair agreement with the experimental observations. Full article

(This article belongs to the Special Issue Light Beams in Liquid Crystals)

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18 pages, 4825 KiB

Open AccessArticle

3D In Situ Stress Estimation by Inverse Analysis of Tectonic Strains

by Mingwei Guo, Shunde Yin, Chunguang Li and Shuilin Wang

Appl. Sci. 2021, 11(11), 5284; https://doi.org/10.3390/app11115284 - 7 Jun 2021

Cited by 2 | Viewed by 2444

Abstract

The determination of a 3D engineering-scale in situ stress field is essential in underground rock mechanics and engineering. The inverse analysis method is a useful technique to determine the in situ stress around the zone of interest. This paper presents a new approach [...] Read more.

The determination of a 3D engineering-scale in situ stress field is essential in underground rock mechanics and engineering. The inverse analysis method is a useful technique to determine the in situ stress around the zone of interest. This paper presents a new approach with tectonic strains based on traditional stress-based or displacement-based inverse analysis. In this approach, there are only six tectonic strain variables at the boundary to be optimized, which does not need to select the stress or displacement boundary conditions as the traditional inverse analysis. Therefore, the proposed approach has a better clarity. The proposed approach is applied to the determination of the engineering-scale in situ stress of the underground powerhouses of the Three Gorges Project, and the results are compared with those obtained by traditional approaches. The comparison further shows that the proposed method has better accuracy than traditional methods. Full article

(This article belongs to the Special Issue Advances in Geotechnical Engineering Ⅱ)

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13 pages, 2644 KiB

Open AccessArticle

Calibration of Finn Model and UBCSAND Model for Simplified Liquefaction Analysis Procedures

by Jui-Ching Chou, Hsueh-Tusng Yang and Der-Guey Lin

Appl. Sci. 2021, 11(11), 5283; https://doi.org/10.3390/app11115283 - 7 Jun 2021

Cited by 12 | Viewed by 3895

Abstract

Soil-liquefaction-related hazards can damage structures or lead to an extensive loss of life and property. Therefore, the stability and safety of structures against soil liquefaction are essential for evaluation in earthquake design. In practice, the simplified liquefaction analysis procedure associated with numerical simulation [...] Read more.

Soil-liquefaction-related hazards can damage structures or lead to an extensive loss of life and property. Therefore, the stability and safety of structures against soil liquefaction are essential for evaluation in earthquake design. In practice, the simplified liquefaction analysis procedure associated with numerical simulation analysis is the most used approach for evaluating the behavior of structures or the effectiveness of mitigation plans. First, the occurrence of soil liquefaction is evaluated using the simplified procedure. If soil liquefaction occurs, the resulting structural damage or the following mitigation plan is evaluated using the numerical simulation analysis. Rational and comparable evaluation results between the simplified liquefaction analysis procedure and the numerical simulation analysis are achieved by ensuring that the liquefaction constitutive model used in the numerical simulation has a consistent liquefaction resistance with the simplified liquefaction analysis procedure. In this study, two frequently used liquefaction constitutive models (Finn model and UBCSAND model) were calibrated by fitting the liquefaction triggering curves of most used simplified liquefaction analysis procedures (NCEER, HBF, JRA96, and T-Y procedures) in Taiwan via FLAC program. In addition, the responses of two calibrated models were compared and discussed to provide guidelines for selecting an appropriate liquefaction constitutive model in future projects. Full article

(This article belongs to the Section Earth Sciences)

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